Removable plug-in connections are used in various applications. An example of this type of connection is described in German Patent DE 3734948 A1.
Plug-in connections of this type are intended for high-pressure lines, in particular, for brake lines in the construction of motor vehicles. They are usually comprised of a cylindrical receiving housing with a central receiving chamber for the insertion of a tubular plug-in part that is provided with a peripheral retaining rib, as well as with an enlarged receiving chamber on the insertion side for the embedding of locking elements with inwardly pointing retainer wedges, which are clamped in the direction of the interior by an encompassing, separate retaining ring made of stainless steel. When the plug-in part is inserted, the retainer wedges are pressed apart against the elastic force by its retaining rib and are brought together again after the plug-in part has penetrated completely, so that the retaining surfaces pointing in the direction of the interior engage in a positive fit behind the retaining rib on its back side.
In the case of the known plug-in connection, three retainer wedges held together by an elastic band are embedded in the enlarged receiving chamber of a separate collar sleeve, which is connected with the receiving housing after the retainer wedges are embedded. To produce the connection, the collar sleeve can either be provided on the end of its sleeve with an internal thread that is screwed onto an external thread located on the housing. Or else the sleeve is provided at its back end with a formed-on inner ring which locks into a corresponding groove upon assembly with the housing. Because of the two-part design of the receiving housing, assembly is very cumbersome and thus relatively expensive for a mass-produced article. Moreover, manual skill is also required in order to hold the three retainer wedges together in order to wind the elastic band around them and to embed this loose connection into the enlarged receiving chamber in the collar sleeve.